From: Dan Ehrenberg <dehrenberg@google.com>
Date: Mon, 18 Jul 2011 01:18:51 +0000 (-0400)
Subject: ext4: ignore a stripe width of 1
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=3eb08658431abd65c0fe6855d1860859c2d416f7;p=openwrt%2Fstaging%2Fblogic.git

ext4: ignore a stripe width of 1

If the stripe width was set to 1, then this patch will ignore
that stripe width and ext4 will act as if the stripe width
were 0 with respect to optimizing allocations.

Signed-off-by: Dan Ehrenberg <dehrenberg@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 7910e61809e7..143d763729b4 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2384,17 +2384,25 @@ static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
 	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
 	unsigned long stripe_width =
 			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
+	int ret;
 
 	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
-		return sbi->s_stripe;
-
-	if (stripe_width <= sbi->s_blocks_per_group)
-		return stripe_width;
+		ret = sbi->s_stripe;
+	else if (stripe_width <= sbi->s_blocks_per_group)
+		ret = stripe_width;
+	else if (stride <= sbi->s_blocks_per_group)
+		ret = stride;
+	else
+		ret = 0;
 
-	if (stride <= sbi->s_blocks_per_group)
-		return stride;
+	/*
+	 * If the stripe width is 1, this makes no sense and
+	 * we set it to 0 to turn off stripe handling code.
+	 */
+	if (ret <= 1)
+		ret = 0;
 
-	return 0;
+	return ret;
 }
 
 /* sysfs supprt */